Tool for scraping and smoothing plastic and metal surfaces



Feb. 23, 1965 E. CREPEAU ETAL TOOL FOR SCRAPING AND SMOOTHING PLASTIC AND METAL SURFACES Filed May 2. 1962 PATENT AGEN 3,170,373 V TOOL FOR SCRAPING AND SMOOTI-IING PLASTIC AND METAL-SURFACES Ernest Crepeau,.53 Youville Blvd., Chateauguay, Quebec, 9 Canada, andStanislas Lapierre, 456 Ch. LacSL-Louis, Lower Woodland, Quebec, Canada, assignors of thirty- I v three and one-third percent to Jeanne Dagenais ne .Descham'ps, Chateauguay, Quebec, Canada p 7 Filed May 2, 1962, Ser. No. 191,809: f

Claims. (Cl. 90-1 j 1 The present invention relates to aportable power tool to be usedin connection With auto body work and more particularly to a power tool for scraping and smoothing the plastic and/ or metal surfaces of the repaired portions of an automobile body prior to paintingthe same.

n The conventional way of scraping and smoothing out repaired surfaces of automobile bodies before painting the same, consists of using. sandpaper and files. This is a time consuming operationand moreover it producesconsiderable dust and the sand paper must be replaced very often. I r r V Consequently, the general object ofthe present invention resides in the provision of'a portable power tool for scraping and smoothing .out plastic and/ or metal surfaces of automobile bodies, and the like, which consider: ably accelerates the scraping and smoothing out operation as compared to the conventional methods for carrying out said operation.

United States Pat n I 3,170,373 Ce r s Feb. 23', 19

13 is screwed on threaded portion 11 of shaft 7 and abuts 1.

against flange 12. Disc 13 is parallel toand slightly spaced downwardly from the bottom face of circularex- I tension 4. J

A pair of parallel slots'lfi of dovetailed cross section are formed in the lower face of disc 13 and are equally spaced on each side of the rotational axis of the disc 13. A pair of cutter bits 15 are rigidly secured to the disc 13 4 by engaging the slots 14. Each cutter bit'15 consistsofia 3 Another important, object of the present invention resides the provisiorikof a portable power tool of the character described which does not produce any (lust duringscrapingjandsmoothingout.

Another important object of the present invention re sides in the provision {of a portablepowertool ofthe character described usingja rotary high speed cutter," the v shank 16 of dovetailed cross section slidably fitted withv in the slot 14 and firmly secured in position by lateral set screws 17 threadedly engaging bores made-in disc 13 and abutting against the shank 16. 1 Each cutter bit has a head. 13 integral with shank 16 and protruding outwardly from the peripheral face of the disc 13; each head 18 'for'ms a cutting edge 19 and'the two cuttinggedges liein a common plane parallel to andspaced downwardly from the lower face of the disc 13. i v s p i The front edge of the base frame 1 is concave-to make room for the heads 18 of the cutter blades 15 during their circular movement. n H

A flexible resilient blade 21 of relatively thin gauge is secured by bolts 22 at its front-portion to the front portion of the'underface ltl ofbase frame l Blade 21 has cutter bits of which are madefof carbide steelfor similar high speed alloy which can be easily"'sharpened when Worn out and which will j- V y long service without replacement; m a

Another important" object of the pres'ent invention iresides in the provision 'ofc-a'power tool'of the'character described provided with'means for "guiding the po over curve'd' surfaces of-an-automobile body..

1 Yet 'another important object of. "the present invention resides in the provision of'a' powertool of the character, described in which means are provided for easily adjusting the level of the cutter bits with respect to the guiding plate, of the'tool.

"The foregoing and other important objectsof the present invention will become moreapparent during the following disclosure and by referring to the drawings, in which: p

FIGURE 1 is a side elevation of the tool of the present invention; 7 n FIGURE 2 is a bottom plan viewof the same; I FIGURE 3' isan enlargedside elevation of the rotary cutter; and V 1 FIGURE 4 is a partial cross-section of the rotary cutter. Referring now more particularly to the drawings in which like; reference characters indicate like elements throughout, the tool of'the present invention comprises an elongatedsubstantially fiat base frame 1 preferably made of acasting of aluminum or the like light weight metal, having spaced upstanding ears 2 to which is secured a handle 3. Base frame 1 is provided at its front end with a circular extension 4 having a peripheral upwardly extending flange 5 and to which is .secured a cylindrical housing 6 for an electric motor (not shown). The shaft a shape and dimensions" corresponding. to, sa'idimid e f face'liiwith a concave front edge-21.3 corresponding .tothe front edgeof base frame 1 andf'arounded,rear1edgeg24 corresponding to the rounded rear edge 25 of base na e 1; exceptforits attachment byibolts 2 Ehcresilient blade 1 protrudes downwardly from the lowe face 111p tool 21fis freefof .the base fralne 1. Its'r'ear end portion is engaged; an "adjustable screw ,26 which threaded through; the rear .end portion of the base fraine l and frame 1. Adjustablescrew manually adjusted 'L turningits knurled head 27.. n

An-electric switch 28 ,"preferablymountedon the front portion of handle 3, controls the electriemotor of'the tool.

:The housing 6 ofthe electric motor is provided with a top threaded bore 29 and a lateral threaded bore 30 for threadedly receiving the threaded stem of a hand grip 31 which can thus be secured in any one of two selected positions, in which it will project either laterally forwardly from the tool or from the top of the housing 6. i

The tool of the present invention is used as follows:

The cutter bits 15 and flexible resilient blade 21 are positioned on the metal or plastic. surface to be scraped and smoothened out and the screw 26 is secrewed in or unscrewed in order to adjust the curvature of the resilient blade 21 to correspond to the curvature of the surface 7 of the rotor of the electric motor extends through an opening made in the extension 4. Housing 6 is adjustably secured to extension 4, by means of bolts 8 freely passing portion to be scraped and smoothened out. 'Then the electric motor is started by means of switch 28, whereby the rotating cutter bits 15 scrape the plastic or 'metal in the form of chips similar to those obtained with a plane when smoothing out wood, but of a smaller size. The tool is held with the hands by means of handle 3 and hand grip 31. After one or more passes have been eifected in a given surface area of similar curvature, the motor is stopped and the screw 26 is again adjusted to curve the resilient blade v 21 in accordance with an adjacent surface portion of another curvature. The smooth ing out operation is then repeated on this new surface portion. .1 Y

The depth of cut is easily adjusted'by screwing or unscrewing the spring pressed bolts 8 which serve to space more or less the motorhousing 6 from extension 4 and consequently to adjust the level of the rotary disc 13 and cuttingtedges 19 of the cutter bits 15 with respect to the underface of the attached portion ofthe resilient blade 21. The adjustment is selected such as to have the cutting edges 19 substantially in the plane of the lower surface of said attached portion of the resilient blade 21.

The cutting edges 19 are easily sharpened by simply unscrewing the set screws 17 and removing the ent re cutter bits 15 for sharpening on a suitable grinding wheel. If desired, the whole cutter disc 13 can be unscrewed from shaft 7 byholding nut shaped flange 12 against rotation.

It has been found that the device of the present invention is very fast in operation and-does not produce any dust. It is especially efilcient on the type of plastic repairs which are made to bodies of automobiles and which are very hard to file down with an ordinary file or with sand paper.

The power tool of the invention is also efiicient on any other metal surfaces, such as lead, galvanized iron and the like, normally used in body work.

While a preferred embodiment in accordance with the present invention has been illustrated and described, it is understood that various modifications may be resorted to without departing from the spirit and scope'of the appended claims.

What we claim is: 1. A portable power tool for scraping and smoothing out metal and plastic surfaces of variable curvatures comprising an elongated base frame having an extension at one end thereof, a power driven rotary cutter carried by said end extension, a flexible resilient blade extending adjustingmeans mounted at the end of said base frame, a

opposite said extension, engageable with said resilient blade for varying the radius of curvature of the same.

2.;A portable power tool as claimed in' claim 1, wherein said adjusting means consist-of a manually rotatable screw in threaded engagement with said base frame and passing throughfthe samepand having one end abutting against said resilient blade at the fere end portion thereof. a

3. A portable power tool as claimed in claim 1, wherein said power driven rotary cutter is adjustably secured to said extension to adjust the level of said rotary cutter with respect to the underface of said resilient blade.

4. A portable power tool comprising a base frame of elongated shape having a flat continuous underface, a handle secured to said base frame and protruding upwardly therefrom at the top face thereof, a flexible resilient blade secured at one end to one end of the underface of said base frame and free therefrom over the remaining portion of said underface and flexible blade, an adjusting screw threadedly engaging and pasing through the opposite end of said base frame and engageable with the free end portion of said'blade to vary the radius of curvature of said blade, an extension integral with said base frame and protruding from the end thereof to which said resilient blade is attached, said extension being in circular form and having its underface lying in a plane parallel to and spaced upwardly from the underface of said base frame, an electric motor mounted on said tool and having a motor shaft passing through said extension, a disc secured to said shaft under said extension, cutter bits removably secured to said disc and having cutting edges lying in a common plane at substantially the level of said resilient blade in the region of said blade attached to said base frame, said cutting edges lying in a plane spaced downwardly from said rotary disc.

5. A portable power tool as claimed in claim 4, including means for adjustably securing said motor to said extension for varying and adjusting the level of the cutting edges of said cutter bladeswith respect to said resilient blade.

6. A. portable power tool as claimed in claim 5, wherein said means for adjustably securing said motor to said extension include bolts freely passing through said extension and threadedly engaging the, housing of said motor, and coil springs surrounding said bolt and abutting against said motor'housing and said extension.

7. A portable power tool asclaimed in claim 4, fur

therincluding a hand grip removably secured to thehousing of said motor. I

References Cited in the file of this patent UNITED STATES PATENTS" Greeley May 22, 1956 

1. A PORTABLE POWER TOOL FOR SCRAPING AND SMOOTHING OUT METAL AND PLASTIC SURFACES OF VARIABLE CURVATURES COMPRISING AN ELONGATED BASE FRAME HAVING AN EXTENSION AT ONE END THEREOF, A POWER DRIVEN ROTARY CUTTER CARRIED BY SAID END EXTENSION, A FLEXIBLE RESILIEN TBLADE EXTENDING UNDERNEATH SAID BASE FRAME AND SECURED THERETO ADJACENT SAID ROTARY CUTTER AND FREE OF SAID BASE FRAME FOR THE MAJOR PORTION OF SAID RESILIENT BLADE AND BASE FRAME, AND ADJUSTING MEANS MOUNTED AT THE END OF SAID BASE FRAME OPPOSITE SAID EXTENSION, ENGAGEABLE WITH SAID RESILIENT BLADE FOR VARYING THE RADIUS OF CURVATURE OF THE SAME. 